I will just write this quickly now not going into details much but I want to say.
Yes you can use fire against the enemies. You can just burn them, you can cut their flesh, you can practice fighting every day and get better. This comes with a feel, and it gets better with practice. You can throw bombs at them, make enemies explode from inside, you can make them smaller, bigger, cut their organs out, torture them, do whatever. You can practice many magic spells on them. PRACTICE IS THE KEY. Throught the practice you become deadly. Keep also smashing, hitting the enemy, learn how to protect yourself, try not to allow them to sink too deeply to you. Sometimes just ignoring can help a lot.. You can just imagine them being smashed, or broken, disappearing.... You can practice making shields on the astral and practice manifesting it better. Magic can manifested better. You must practice this more to get to a certain level.
You can really blow up even parts of the planets or planet, some of their bodies, and huge damage can be done. You can practice this in some churches and similar when you start getting a bit of a feel for it. Things can be teleported too and even made fully on the material if you are lucky with your magic. This all requires a skill.
Fighting on the astral
Re: Fighting on the astral
When I say bodies I mean bodies that are parts of our soul, and that are finally making our physical body too. There are many layers and those who have died might see that for themselves. Thes might be splitting into several soul pieces and bodies until they are fully weakened.